Metaphors are very important, in politics as elsewhere. Michael O'Hare tries a bit to pick apart the metaphor of escalation as a "hail mary" pass, but I think he misses the central point. In a football game, the point of a hail mary play is that it's a desperate gamble embarked upon by a team that has nothing to lose. It's a risky, low percentage play and running it tends to increase your chances of losing the football game. But when the only alternative is certain defeat, it looks more appealing. This, however, is because all losses are equal in football.

Wars peripheral to the national interest aren't like that. Leaving Iraq in a shambles will have bad results, possibly even very bad results, but it's not as if we need to attempt one last desperate gamble or else the nation faces certain destruction.

The point of view from which the hail mary metaphor makes the most sense is if your primary concern is not the interests of the United States of America but the reputation of George W. Bush and other leading architects of war. From that point of view, the difference between initiating and then losing a war at great cost and initiating and then losing a war at even greater cost really is minimal, much like in a football game. From Bush's point of view, conceding that his Iraq policy has failed is so catastrophic to his ego and reputation that it makes perfect sense to ask other people to bear any burden and pay any price for even the smallest sliver of a hope of even deferring the problem successfully. For the country, though, it doesn't make sense at all.